Hiccups in Newborns Might Help Baby Brains Wire-Up

By Linda Carroll

November 13, 2019

(Reuters Health) - A long string of hiccups in a newborn can make parents uneasy. But researchers now say that those hiccups may aid in the baby's brain development.

Each time a newborn hiccups, three brain waves are triggered, a large one and two smaller ones, a small new study finds. And those brain waves may help babies learn how to regulate their breathing, according to the report published in Clinical Neurophysiology.

"Hiccups may not be just a 'nuisance,'" said the study's lead author, Kimberley Whitehead, a research associate at University College of London. "They may play an important developmental function by strengthening the brain's sensory 'map' of the breathing muscles. Babies' brains appear to be registering the 'feel' of the hiccup, as they sense the movement of the diaphragm."

A typical bout of hiccups can last 8 minutes, Whitehead and her colleagues noted. While that may be worrisome to some parents, it's completely normal and quite possibly a necessary part of babies learning how to exert voluntary control over their breathing, Whitehead said.

To learn more about the potential purpose of hiccups in babies, Whitehead and her colleagues studied 13 newborns in a British neonatal ward who were experiencing hiccups. The group of babies included some who were born full term and some who were pre-term.

Electrodes were placed on the babies' scalps to measure brain activity in a procedure known as electroencephalography (EEG). Movement sensors placed on the infants' bellies provided information on when the baby was hiccupping. Recordings of the two types of measurements were temporally linked so researchers could determine if there could be a connection between the hiccups and certain types of brain activity.

After looking at the two sets of recordings, Whitehead and her colleagues determined that each hiccup was associated with a complex pattern of brain activity.

The researchers found that contractions of the diaphragm muscle from a hiccup were associated with three brain waves, the third of which looked similar to what is evoked when a baby hears a noise. They suspect that the newborn's brain could be linking the 'hic' sound of the hiccup with the feel of the diaphragm muscle during contraction.

The first two waves may be associated with the brain wiring up circuits that control breathing, Whitehead suggested.

So, what about hiccups in adults?

"There is no evidence that hiccups do anything good for us once we've grown up," Whitehead said in an email. "Certainly the function that appears to be relevant in infants doesn't seem to be relevant in adults because the maps of our bodies in our brain are well developed from early infancy."

SOURCE: http://bit.ly/2X7vibi

Clin Neurophysiol 2019.